a. Field of Invention
This invention pertains to a repeater for television signals, and more particularly to a repeater in which a composite received television signal is separated into a visual component and an aural component, each component is amplified and then the amplified signals are recombined into a composite signal for retransmission.
b. Description of the Prior Art
Due to the large demand for RF signal channels, especially in the range of cable television signals, the spacing between adjacent channels has been reduced considerably. With the advent of the multichannel multi-point distribution service (MMDS) this spacing has shrunk to a point that television signal channels are virtually adjacent. One of the problems associated with this type of transmission is that spurious out-of-band by products are generated in repeater stations which degrade the composite video signals. It was found that to overcome this problem, repeaters has to separate each composite signal into an aural and a visual component and process them separately. One method of performing this separation was to use a brute force filtering approach. This approach consisted of using a relatively wide (about 5 Mhz) vestigial side band SAW filter to pass the visual carrier while attenuating the aural signal. A very narrow L-C filter stage was used to pass the aural signal. However the narrow filter stage created amplitude and frequency variations in the aural signal which degrades the signal and stereo signal separation.